1. Field of the Invention
The present invention relates to a supporting structure of a closing resistor unit for a circuit breaker, and more particularly, to a supporting structure of a closing resistor unit for a circuit breaker, which improves the supporting structure of the closing resistor unit fixed to a fixed portion provided in the circuit breaker to stabilize the structure of the closing resistor unit and prolongs the lifespan of the circuit breaker.
2. Background of the Invention
A gas insulation switchgear is a switchgear that uses sulfur hexafluoride (SF6) gas, commonly referred to as GIS.
The GIS may be miniaturized by encapsulating a circuit breaker efficient in extinction capability and stable in insulation, a switch, and a busbar connector, which are filled with SF6 gas, in a sealed container, and its stability in use may be improved, whereby the GIS may be used in various fields.
For a circuit breaker provided in a large-scaled GIS that has a voltage supply of 170 kV or higher, a closing resistor unit is used to resist the overvoltage generated when a moving portion is inserted in to the fixed portion of the circuit breaker.
A circuit breaker based on a conventional closing resistor unit is shown in FIGS. 1 and 2.
As shown in FIGS. 1 and 2, the circuit breaker of a GIS used for 170 kV or higher voltage includes a moving portion 10, a fixed portion 20 into which the moving portion 10 is inserted and made contact, a closing resistor moving portion 30 provided with a closing resistor moving portion point of contact 31, a closing resistor unit 40 provided with a closing resistor unit point of contact 41 that contacts with the closing resistor moving portion point of contact 31.
At this time, the moving portion 10 is provided with a guide 10 formed to make a stable contact between a fixed point of contact 21a formed inside the fixed portion 20 and the moving portion 20. The guide 11 guides a rod 21 formed inside the fixed portion 20 into the inside of the moving portion 10, whereby the fixed point of contact 21a formed at the end of the rod 21 is in contact with the moving portion 10.
The contact of the closing resistor unit 40 of the conventional GIS described above is performed as follows.
First, if the moving portion 10 moves towards the fixed portion 20 in a state that the closing resistor unit 40 is attached to the side of the fixed portion 20, the rod 21 formed inside the fixed portion 20 is inserted into the moving portion 10.
At this time, since the fixed point of contact 21a is formed at the end of the rod 21, the fixed point of contact 21a may be guided by the guide 11 and thus inserted into the moving portion 10, thereby making contact with the moving portion 10.
Meanwhile, when the fixed point of contact 21a is in contact with the moving portion 10, a contact is generated between the closing resistor unit point of contact 41 and the closing resistor moving portion point of contact 31, whereby an impact is given to the closing resistor unit 40.
However, in the conventional circuit breaker described above, the impact generated by the contact between the closing resistor unit point of contact 41 and the closing resistor moving portion point of contact 31 is directly transferred to the closing resistor unit 40 or its neighboring instruments, whereby not only the closing resistor unit 40 but also the joints connected to the closing resistor unit 40 may be damaged, leading to a problem that structural stability of the closing resistor unit 40 inside the circuit breaker is remarkably deteriorated.
Also, since the structural stability of the closing resistor unit 40 inside the circuit breaker is remarkably deteriorated, another problem occurs in that the lifespan of the circuit breaker is greatly shortened.
Finally, other problem occurs in that attaching or detaching the closing resistor unit 40 to or from the fixed portion 20 is arduous.